l!^'lf> I Michael, cl at. : Hi/dnxjropli ic I\( cards of Scripps I until nlinn '1\ 1 



Figs. A-C. (>|)eiation of Serial Closing Apparatus 

 Fig. A. Nets closed, rea<ly for descent. Note especially the following: the 

 clamps (cl.) by which the apparatus is attached to the cable (c) ; rod trip (r.t.) 

 which, upon closure of water-bottle lids (Id.), releases the chain (rh.) support- 

 ing terminal end of rod (r.) ; tension on nets due to accumulator spring (a). 

 which insures proper adjustment of T on supporting rod r.;.net buckets (6). 

 consisting of stork sheeting which has proved more satisfactory than bronze; 

 messengers (m^ and m*) suspended from lower ends of trips (t) in readiness for 

 opening and closing next lower pair of nets. 



Fig. B. After descent of first messenger, m\; nets open, ready for towing. 

 Note especially the following: position of net rims (rm), which have been 

 turned by the coiled springs (c..?.) at right angles to the closing covers (co.), the 

 latter remaining in same position as in figure A; closing covers (co.) consist 

 of bronze rims to which cojiper screening of finer mesh than netting is attached 

 (this is readily replaced by thin bronze plates when small-meshed nets are 

 used); water bottle (w.b.) also serves as axis about which net rims (rm.) have 

 revolved; messenger m'., shown in figure A, has been released. 



Fig. C. After descent of second messenger, m".; nets closed, water bottle 

 (iF.h.) closed, thermometer rack (i.r.) reversed, and supporting rod (r.) released, 

 ready for hoisting. Note especially the following: pcrxpective at riqht angles to 

 that of figures A and B; excentric rods e. (shown also in figure B), by which 

 water-bottle lids (Id.) were closed when thermometer rack (t.r.) was reversed 

 by the rack spring (r.s.) and locked by the latch (/.), all of which is possible 

 only after both closing covers (co.) have revolved against the net rims (rm.) ; 

 messenger in'., shown in figures A and B, has been released. 



one depth and the Iwtth' to clo.se at another, rrgardh.t.<> of ihc inclina- 

 tion of llic vahlf. 



3. It is mechanically impossible for the thermometers to reverse 

 or the water bottle to close unless both nets are closed ; thus, a valuable 

 means i.s at hand for determining the approximate depth of closure 

 in case it differs from that indicated by the amount of cable out. 



4. The heavy weight .suspended from the end of the cable may 

 remain submerged when attaching and removing the apparatus, thus 

 permitting collecting in rougher seas than would otherwise be possible. 



5. The rod (r.) to which the net buckets (b.) are attached is so 

 supported from the frame that when the nets are closed it is released 

 and hangs below the frame (compare figs. A and C), while the 

 apparatus is being hoisted, thus preventing undue strain upon the 

 netting. 



The only disadvantages so far suggested are three : 



1. The dynamical pressure of water on more than two of the 

 duplicate nets of each apparatus may so deflect the cable as to prevent 

 the messengers from properly opening or closing the nets, unless a 

 weight of at least fifty pounds is suspended from the end of the 

 cable for each apparatus attached. 



2. Even under the most favorable conditions of the sea, it is difficult 

 and cumbersome to attach a fifty-pound apparatus to and remove it 

 from the cable. 



